Streptokinase recovery by cross-flow microfiltration: study of enzyme denaturation

During streptokinase (SK) recovery by cross-flow microfiltration (CFMF), a loss of activity of 14.4% was observed, after the initial volume was concentrated 8-fold (VCF = 8.0); 51.5% of the activity was recovered in the filtrate and 34.1% remained in the retentate. Immunological experiments using polyclonal antibodies against SK have demonstrated that SK activity loss during CFMF processes could be related to denaturation of SK, forming molecules of lower or no activity. Accumulation of denatured SK in the retentate suggests that denaturation could be the results of an aggregation phenomenon (as has been demonstrated by light scattering and chromatographic studies), leading to the formation of protein aggregates that are retained by the microfiltration (MF) membrane, affecting the fouling phenomenon and the concentration in the retentate of permeable molecules.